mpi_group_size(3)
NAME
MPI_Group_size - Returns the size of a group.
SYNTAX
C Syntax
#include <mpi.h>
int MPI_Group_size(MPI_Group group, int *size)
Fortran Syntax
- INCLUDE 'mpif.h'
MPI_GROUP_SIZE(GROUP, SIZE, IERROR) - INTEGER GROUP, SIZE, IERROR
C++ Syntax
#include <mpi.h>
int Group::Get_size() const
INPUT PARAMETERS
group Group (handle).
OUTPUT PARAMETERS
size Number of processes in the group (integer).
IERROR Fortran only: Error status (integer).
DESCRIPTION
MPI_Group_size returns in size the number of processes in the group.
Thus, if group = MPI_GROUP_EMPTY, then the call will return size = 0.
On the other hand, a call with group = MPI_GROUP_NULL is erroneous.
ERRORS
Almost all MPI routines return an error value; C routines as the value
of the function and Fortran routines in the last argument. C++ functions do not return errors. If the default error handler is set to
MPI::ERRORS_THROW_EXCEPTIONS, then on error the C++ exception mechanism
will be used to throw an MPI:Exception object.
- Before the error value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job, except for
I/O function errors. The error handler may be changed with
MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN
may be used to cause error values to be returned. Note that MPI does
not guarantee that an MPI program can continue past an error.